The present invention relates to an occupant protection safety system, and more particularly to a safing system which prevents inadvertent deployment.
If a vehicle crash or roll-over event occurs, occupant protection safety systems installed in the vehicle must be activated in timely fashion; these include, for example, roll-over bars, belt tensioners, front and side airbags, etc.
Satellite sensors are typically provided to sense vehicle frontal, side, or roll-over crash events. The satellite sensors communicate with a safety controller which physically controls and diagnoses faults in the occupant protection safety systems.
To ensure also that the occupant protection systems are in fact activated only in the event of a crash or a roll-over, incorrect detections must be excluded to the greatest extent possible. Further, component failures must be assured of not inadvertently deploying the safety systems. It is known to provide redundant microcontrollers and sensors to assure no single component failure will result in inadvertent airbag deployment. However, redundant components may result in an expensive system in which the redundant components may provide conflicting data.
Accordingly, it is desirable to provide an occupant protection activation system which does not require redundant microcontrollers and minimizes the likelihood of inadvertent deployment, due to a microcontroller failure in the satellite sensor.
The vehicle occupant protection activation system according to the present invention includes one or more satellite sensors which communicate with a safety controller. The satellite sensor(s) and safety controller assure that the occupant protection systems are activated only in the event of vehicle crash or roll-over.
In operation, the satellite sensors communicate with the safety controller to identify whether a heightened likelihood of a vehicle crash event or roll-over exists. If a heightened likelihood of such an event exists the corresponding satellite sensor sends a safing message to the safety controller. When the safing message is received by the safety controller it responds to the satellite sensor with a safing response including a seed message therein. The seed message is temporarily stored in the satellite sensor and is also stored by the safety controller. The safety controller is now xe2x80x9carmedxe2x80x9d for the corresponding safety system.
The satellite sensor confirms whether the safety system deployable vehicle event is, in fact, actually occurring. If it is determined that the event requires deployment, the satellite sensor sends a deploy message to the safety controller that includes the seed message therein to authenticate the command. The safety controller is thus assured that the deploy command is authorized and inadvertent deployment is prevented, which could have been caused by a failure in the satellite sensor microcontroller. A microcontroller failure in the satellite sensor would prevent it from both receiving and transmitting the seed message to the safety controller, while concurrently determining a deployable event has occurred.